Authorities have learned the sad truth about the Texas explosion that killed 15 people three years ago

Federal investigators confirm that the fire and explosion at West Fertilizer Company in April 2013 was started intentionally and was a criminal act.

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Authorities said the fire was set but did not call it arson.

FULL STORY: West, Texas fertilizer plant blast ruled a "criminal act" https://t.co/T3BTRWM66G pic.twitter.com/ZKkCHhmbuT

— ABC7 Eyewitness News (@ABC7) May 11, 2016

The explosion killed 15, 10 of whom were first responders. A grand total of 200 people were hurt. As many as 120 homes in West, Texas, were destroyed.

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According to FOX4, the ATF’s ongoing investigation has led to the conclusion that the fire was started intentionally.

JUST IN: 2013 explosion, fire at West, Texas fertilizer plant was criminal : https://t.co/dodFiCBA31 pic.twitter.com/t4MSQb8u4W

— WTHR.com (@WTHRcom) May 11, 2016

A $52,000 reward is being offered for anyone with information about the person who started the deadly blaze.

ATF: West, Texas Plant Explosion a Criminal Act, https://t.co/IphPMECdF7 pic.twitter.com/Eim3Nq3Q5y

— Firefighter Nation (@firenation) May 11, 2016